||Networks / Pajek
|Package for Large Network Analysis
Some hints on
working with extremely large networks in Pajek
Extremely large networks
The current limit on the size of Pajek network is
almost 10 million vertices, the number of lines is
limited by available (virtual) memory (limited by
physical constraints to 2 G). The use of virtual
memory substantially reduces the performance of Pajek.
Use Windows Task Manager / Performance to monitor
the usage of memory.
We consider a network as extremely large if it
occupies more than half of the available physical
memory on the computer. An example of such network
is the US patents network
(3774768 vertices and 16522438 arcs)
The simplest solution to deal with extremely large
networks is to increase, if still possible, the
physical memory of your computer.
To support work with such networks Pajek provides
some special options:
Input without vertex labels
Options / Read/Write
we can switch OFF the
Read vertices labels.
The network will
be read without labels, thus saving a lot of
Adding labels to small derived subnetworks
You can add the labels later to a subnetwork
using the option
Net / Transform / Add / Vertices Labels from File
To speed up reading of network or to be able to
select the labels, you may consider
to split the network data to file without labels
and file(s) of labels. You can even have several
files of labels (short/long, different languages).
For larger networks Pajek asks the user whether
to store the resulting network as a new network
or to transform the current network (thus saving
Disposing of data
For all its data structures Pajek provides in the
menu the disposing option allowing to the
user to dispose the data that are not needed,
thus freeing the corresponding memory.